Auto Zombie and Spider Farm

[DontH8AndDon8]

On YouTube I see that most of the automatic zombie farms use cactus to kill them, but isn't it simpler to use a fall damage grinder? I haven't made an auto zombie farm yet so I'm wondering what the best method is. Also, how should I setup an auto spider farm, would I use cactus?

 

[TarSe]

If you use the spawners that the game gives you, you will have to make 40/70 blocks high (depends on the tough), a farm per fall can be a hindrance if you don't use lvl 1 spawners

 

[FractalCake]

On YouTube I see that most of the automatic zombie farms use cactus to kill them, but isn't it simpler to use a fall damage grinder? I haven't made an auto zombie farm yet so I'm wondering what the best method is. Also, how should I setup an auto spider farm, would I use cactus?

I like fall damage more than cactus. With cactus you run the risk of losing drops. I have a spider farm video as well as fall damage grinder video on my YT (link in my signature)

The fall damage grinder would work with any mob (other than spiders and ocelots)